The brain in evolution and involution

1997 ◽  
Vol 75 (6) ◽  
pp. 651-667 ◽  
Author(s):  
André Parent
Keyword(s):  
Basal Ganglia ◽  
Substantia Nigra ◽  
Functional Organization ◽  
Current Model ◽  
Brain Structures ◽  
Subcortical Structures ◽  
Severe Motor ◽  
Cortical Inputs ◽  
Neuronal Systems ◽  
The Brain

This paper provides an overview of the phylogenetic evolution and structural organization of the basal ganglia. These large subcortical structures that form the core of the cerebral hemispheres directly participate in the control of psychomotor behavior. Neuroanatomical methods combined with transmitter localization procedures were used to study the chemical organization of the forebrain in each major group of vertebrates. The various components of the basal ganglia appear well developed in amniote vertebrates, but remain rudimentary in anamniote vertebrates. For example, a typical substantia nigra composed of numerous dopaminergic neurons that project to the striatum already exists in the brain of reptiles. Other studies in mammals show that glutamatergic cortical inputs establish distinct functional territories within the basal ganglia, and that neurons in each of these territories act upon other brain neuronal systems principally via a GABAergic disinhibitory output mechanism. The functional status of the various basal ganglia chemospecific systems was examined in animal models of neurodegenerative diseases, as well as in postmortem material from Parkinson's and Huntington's disease patients. The neurodegenerative processes at play in such conditions specifically target the most phylogenetically ancient components of the brain, including the substantia nigra and the striatum, and the marked involution of these brain structures is accompanied by severe motor and cognitive deficits. Studies of neural mechanisms involved in these akinetic and hyperkinetic disorders have led to a complete reevaluation of the current model of the functional organization of the basal ganglia in both health and disease. Key words: brain phylogeny, basal ganglia, neurotransmitters, neurodegenerative disorders.

scholarly journals Increased Callosal Connectivity in Reeler Mice Revealed by Brain-Wide Input Mapping of VIP Neurons in Barrel Cortex

2020 ◽  
Author(s):  
Georg Hafner ◽  
Julien Guy ◽  
Mirko Witte ◽  
Pavel Truschow ◽  
Alina Rüppel ◽  
...  
Keyword(s):  
Long Range ◽  
Cortical Neurons ◽  
Barrel Cortex ◽  
Projection Neurons ◽  
Subcortical Structures ◽  
Virus Tracing ◽  
Cortical Inputs ◽  
Callosal Projection ◽  
To Receive ◽  
The Brain

Abstract The neocortex is composed of layers. Whether layers constitute an essential framework for the formation of functional circuits is not well understood. We investigated the brain-wide input connectivity of vasoactive intestinal polypeptide (VIP) expressing neurons in the reeler mouse. This mutant is characterized by a migration deficit of cortical neurons so that no layers are formed. Still, neurons retain their properties and reeler mice show little cognitive impairment. We focused on VIP neurons because they are known to receive strong long-range inputs and have a typical laminar bias toward upper layers. In reeler, these neurons are more dispersed across the cortex. We mapped the brain-wide inputs of VIP neurons in barrel cortex of wild-type and reeler mice with rabies virus tracing. Innervation by subcortical inputs was not altered in reeler, in contrast to the cortical circuitry. Numbers of long-range ipsilateral cortical inputs were reduced in reeler, while contralateral inputs were strongly increased. Reeler mice had more callosal projection neurons. Hence, the corpus callosum was larger in reeler as shown by structural imaging. We argue that, in the absence of cortical layers, circuits with subcortical structures are maintained but cortical neurons establish a different network that largely preserves cognitive functions.

The Role of Temporo-parietal Cortex in Subcortical Visual Extinction

2010 ◽  
Vol 22 (9) ◽  
pp. 2141-2150 ◽  
Author(s):  
Luca Francesco Ticini ◽  
Bianca de Haan ◽  
Uwe Klose ◽  
Thomas Nägele ◽  
Hans-Otto Karnath
Keyword(s):  
Basal Ganglia ◽  
Decisive Role ◽  
Brain Structures ◽  
Cortical Lesion ◽  
Critical Aspect ◽  
Subcortical Structures ◽  
Visual Extinction ◽  
Subcortical Brain Structures ◽  
The Right

Visual extinction is an intriguing defect of awareness in stroke patients, referring to the unsuccessful perception of contralesional events under conditions of competition. Previous studies have investigated the cortical and subcortical brain structures that, when damaged or inactivated, provoke visual extinction. The present experiment asked how lesions of subcortical structures may contribute to the appearance of visual extinction. We investigated whether lesions centering on right basal ganglia may induce dysfunction in distant, structurally intact cortical structures. Normalized perfusion-weighted MRI was used to identify structurally intact but abnormally perfused brain tissue, that is, zones that are receiving enough blood supply to remain structurally intact but not enough to function normally. We compared patients with right basal ganglia lesions showing versus not showing visual extinction. In the extinction patients, the contrast revealed cortical malperfusion that clustered around the right TPJ. It seems as if malfunction of this area is a critical aspect in visual extinction not only after cortical lesion but also in the case of subcortical basal ganglia damage. Our results support the idea that a normally functioning TPJ area plays a decisive role for the attentional network involved in detecting of visual stimuli under conditions of competition.

scholarly journals A Brain to Spine Interface for Transferring Artificial Sensory Information

2019 ◽  
Author(s):  
Amol P. Yadav ◽  
Daniel Li ◽  
Miguel A. L. Nicolelis
Keyword(s):  
Sensory Information ◽  
Brain Structures ◽  
Dorsal Column ◽  
Subcortical Structures ◽  
Prosthetic Devices ◽  
Analog To Digital ◽  
Analog To Digital Conversion ◽  
Corticostriatal Plasticity ◽  
Dorsal Column Stimulation ◽  
The Brain

AbstractLack of sensory feedback is a major obstacle in the rapid absorption of prosthetic devices by the brain. While electrical stimulation of cortical and subcortical structures provides unique means to deliver sensory information to higher brain structures, these approaches require highly invasive surgery and are dependent on accurate targeting of brain structures. Here, we propose a semi-invasive method, Dorsal Column Stimulation (DCS) as a tool for transferring sensory information to the brain. Using this new approach, we show that rats can learn to discriminate artificial sensations generated by DCS and that DCS-induced learning results in corticostriatal plasticity. We also demonstrate a proof of concept brain-to-spine interface (BTSI), whereby tactile and artificial sensory information are decoded from the brain of an “encoder” rat, transformed into DCS pulses, and delivered to the spinal cord of a second “decoder” rat while the latter performs an analog-to-digital conversion during a tactile discrimination task. These results suggest that DCS can be used as an effective sensory channel to transmit prosthetic information to the brain or between brains, and could be developed as a novel platform for delivering tactile and proprioceptive feedback in clinical applications of brain-machine interfaces.

scholarly journals The mouse cortico–basal ganglia–thalamic network

Nature ◽  
2021 ◽  
Vol 598 (7879) ◽  
pp. 188-194
Author(s):  
Nicholas N. Foster ◽  
Joshua Barry ◽  
Laura Korobkova ◽  
Luis Garcia ◽  
Lei Gao ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Closed Loop ◽  
Functional Organization ◽  
Dorsal Striatum ◽  
Thalamic Nuclei ◽  
Indirect Pathway ◽  
History Of ◽  
Bona Fide ◽  
External Part ◽  
The Brain

AbstractThe cortico–basal ganglia–thalamo–cortical loop is one of the fundamental network motifs in the brain. Revealing its structural and functional organization is critical to understanding cognition, sensorimotor behaviour, and the natural history of many neurological and neuropsychiatric disorders. Classically, this network is conceptualized to contain three information channels: motor, limbic and associative1–4. Yet this three-channel view cannot explain the myriad functions of the basal ganglia. We previously subdivided the dorsal striatum into 29 functional domains on the basis of the topography of inputs from the entire cortex5. Here we map the multi-synaptic output pathways of these striatal domains through the globus pallidus external part (GPe), substantia nigra reticular part (SNr), thalamic nuclei and cortex. Accordingly, we identify 14 SNr and 36 GPe domains and a direct cortico-SNr projection. The striatonigral direct pathway displays a greater convergence of striatal inputs than the more parallel striatopallidal indirect pathway, although direct and indirect pathways originating from the same striatal domain ultimately converge onto the same postsynaptic SNr neurons. Following the SNr outputs, we delineate six domains in the parafascicular and ventromedial thalamic nuclei. Subsequently, we identify six parallel cortico–basal ganglia–thalamic subnetworks that sequentially transduce specific subsets of cortical information through every elemental node of the cortico–basal ganglia–thalamic loop. Thalamic domains relay this output back to the originating corticostriatal neurons of each subnetwork in a bona fide closed loop.

scholarly journals EFFECT OF NEURODEGENERATIVE CHANGES IN THE BRAIN ON THE FORMATION OF THE DISEASE CLINICAL PICTURE IN PATIENTS WITH MULTIPLE SCLEROSIS

2013 ◽  
Vol 12 (3) ◽  
pp. 52-60 ◽  
Author(s):  
L. N. Prakhova ◽  
Ye. P. Magonov ◽  
A. G. Ilves ◽  
A. A. Bogdan ◽  
G. V. Kataeva ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Clinical Picture ◽  
Cerebral Atrophy ◽  
Brain Structures ◽  
Neurological Impairment ◽  
Disease Assessment ◽  
Control Group ◽  
Subcortical Structures ◽  
Severity Of Disability ◽  
The Brain

The aim of the study was to determine the relationship of global and regional cerebral atrophy and volume of demyelination lesions in the brain with a clinical picture in patients with multiple sclerosis (MS). The study involved 55 patients with MS. Control group included 22 healthy volunteers. Patients were divided into groups according to the severity of disability, the type and duration of disease. Assessment of general and regional atrophy was performed by post-process volumetric segmentation of MRI data, which was acquired at 3T Philips Achieva scanner. The post-processing was done with the FreeSurfer software. It is shown that in MS patients brain atrophy develops both by means of gray matter (including the cortex and subcortical structures), and white matter, along with demyelination. Global and regional atrophy is associated with the severity of disability of patients according to EDSS scale, but not with the duration and type of the disease. Neurodegenerative changes of brain structures evolve with different rates, have different intensity and determine the set of symptoms of neurological impairment and severity of disability, which indicates the presence of certain patterns of the process of atrophy in the brain, forming the clinical picture of the disease.

Subcortical structures: the cerebellum, basal ganglia, and thalamus

2010 ◽  
pp. 4871-4879
Author(s):  
Mark J. Edwards ◽  
Penelope Talelli
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Basal Ganglia ◽  
Movement Disorders ◽  
Subcortical Structures ◽  
Video Material ◽  
The Brain ◽  
Relay Stations

For video material relating to movement disorders, please go to Movement Disorders Videos. Less is known of the function of the cerebellum, thalamus and basal ganglia than of other structures in the brain, but there is an increasing appreciation of their complex role in motor and nonmotor functions of the entire nervous system. These structures exercise functions that far exceed their previously assumed supporting parts as simple ‘relay stations’ between cortex and spinal cord....

Subcortical structures: The cerebellum, basal ganglia, and thalamus

2020 ◽  
pp. 5937-5945
Author(s):  
Mark J. Edwards ◽  
Penelope Talelli
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Cerebral Cortex ◽  
Basal Ganglia ◽  
Feedback Loops ◽  
Sense Organs ◽  
Subcortical Structures ◽  
Stretch Receptors ◽  
The Brain ◽  
Relay Stations

Less is known of the function of the cerebellum, thalamus, and basal ganglia than of other structures in the brain, but there is an increasing appreciation of their complex role in motor and non-motor functions of the entire nervous system. These structures exercise functions that far exceed their previously assumed supporting parts as simple ‘relay stations’ between cortex and spinal cord. The subcortical structures receive massive different inputs from the cerebral cortex and peripheral sense organs and stretch receptors. Through recurrent feedback loops this information is integrated and shaped to provide output which contributes to scaling, sequencing, and timing of movement, as well as learning and automatization of motor and non-motor behaviours.

scholarly journals The leak channel NALCN controls tonic firing and glycolytic sensitivity of substantia nigra pars reticulata neurons

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Andrew Lutas ◽  
Carolina Lahmann ◽  
Magali Soumillon ◽  
Gary Yellen
Keyword(s):  
Basal Ganglia ◽  
Substantia Nigra ◽  
Acetylcholine Receptors ◽  
Muscarinic Acetylcholine Receptors ◽  
Substantia Nigra Pars Reticulata ◽  
Motor Deficits ◽  
Tonic Firing ◽  
Leak Channel ◽  
Individual Mouse ◽  
Severe Motor

Certain neuron types fire spontaneously at high rates, an ability that is crucial for their function in brain circuits. The spontaneously active GABAergic neurons of the substantia nigra pars reticulata (SNr), a major output of the basal ganglia, provide tonic inhibition of downstream brain areas. A depolarizing 'leak' current supports this firing pattern, but its molecular basis remains poorly understood. To understand how SNr neurons maintain tonic activity, we used single-cell RNA sequencing to determine the transcriptome of individual mouse SNr neurons. We discovered that SNr neurons express the sodium leak channel, NALCN, and that SNr neurons lacking NALCN have impaired spontaneous firing. In addition, NALCN is involved in the modulation of excitability by changes in glycolysis and by activation of muscarinic acetylcholine receptors. Our findings suggest that disruption of NALCN could impair the basal ganglia circuit, which may underlie the severe motor deficits in humans carrying mutations in NALCN.

scholarly journals Analysis of the connection of the concentration of iron in basal nuclei with cognitive impairments in patients with hypertension and atherosclerotic encephalopathy in the study of changes in the magnetic susceptibility of the subcortical structures of the

2018 ◽  
pp. 19-25
Author(s):  
M. Petrenko ◽  
S. Grabovetskii
Keyword(s):  
Basal Ganglia ◽  
Vascular Diseases ◽  
Main Group ◽  
Specific Pattern ◽  
Control Group ◽  
Subcortical Structures ◽  
Normal Range ◽  
Basal Nuclei ◽  
Subcortical Nuclei ◽  
The Brain

Vascular diseases of the brain are an important medical and social problem that negatively affects the economy of the country and the life of society as a whole. Discirculatory encephalopathy refers to slowly progressing disorders of the cerebral circulation, in which development of an essential role is played by hypertension, atherosclerosis, diabetes mellitus and other diseases that affect the vessels of the brain. The purpose of the study was to identify a specific pattern of iron accumulation in the subcortical structures of the brain of hypertensive and atherosclerotic encephalopathy patients to improve the diagnostic criteria for the development of cognitive impairment. For the study, 20 patients in the main group with a diagnosis of hypertensive and atherosclerotic encephalopathy were selected, and the control group consisted of 20 patients, the results of which neuropsychiatric tests were within the normal range. According to the results of the study, the accumulation of iron in the basal ganglia is higher in patients with the main group compared with the control group. The exact mechanism for increasing the concentration of iron in the basal ganglia of the patients in the main group is not known, but this study confirms that deposition of subcutaneous iron may be used as a biomarker for early diagnosis of vascular dementia that develops against the background of hypertensive and atherosclerotic encephalopathy. The results of the study reliably established the existence of a negative correlation between hypointensity of subcortical nuclei and neuropsychological parameters in patients with the main group.

scholarly journals Analysis of the connection of the concentration of iron in basal nuclei with cognitive impairments in patients with hypertension and atherosclerotic encephalopathy in the study of changes in the magnetic susceptibility of the subcortical structures

2018 ◽  
pp. 15-21
Author(s):  
M. Petrenko ◽  
S. Grabovetskii
Keyword(s):  
Basal Ganglia ◽  
Vascular Diseases ◽  
Main Group ◽  
Specific Pattern ◽  
Control Group ◽  
Subcortical Structures ◽  
Normal Range ◽  
Basal Nuclei ◽  
Subcortical Nuclei ◽  
The Brain

Vascular diseases of the brain are an important medical and social problem that negatively affects the economy of the country and the life of society as a whole. Discirculatory encephalopathy refers to slowly progressing disorders of the cerebral circulation, in which development of an essential role is played by hypertension, atherosclerosis, diabetes mellitus and other diseases that affect the vessels of the brain. The purpose of the study was to identify a specific pattern of iron accumulation in the subcortical structures of the brain of hypertensive and atherosclerotic encephalopathy patients to improve the diagnostic criteria for the development of cognitive impairment. For the study, 20 patients in the main group with a diagnosis of hypertensive and atherosclerotic encephalopathy were selected, and the control group consisted of 20 patients, the results of which neuropsychiatric tests were within the normal range. According to the results of the study, the accumulation of iron in the basal ganglia is higher in patients with the main group compared with the control group. The exact mechanism for increasing the concentration of iron in the basal ganglia of the patients in the main group is not known, but this study confirms that deposition of subcutaneous iron may be used as a biomarker for early diagnosis of vascular dementia that develops against the background of hypertensive and atherosclerotic encephalopathy.The results of the study reliably established the existence of a negative correlation between hypointensity of subcortical nuclei and neuropsychological parameters in patients with the main group.

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